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Abstract

Existing adaptive autopilots do not usually have an energy saving capability. In addition, the control performance in rough seas often deteriorates so significantly that the autopilot is switched to a conventional PID controller. The first problem often arises from inaccurate approximations in the formulation of the energy cost criterion and the second from poor modelling of the sea wave disturbances. These problems are tackled here by formulating a new dynamic cost function system description and modelling approach. The LQG control strategy is then used to design an optimal controller to perform the course-keeping autopilot task. An advanced PID type controller is used for course-changing, the parameters of which are found from pole placement techniques.

An explicit self-tuning scheme is employed to provide adaptation in varying weather conditions. Simulation results are presented to demonstrate the performance of the proposed autopilot.

Keywords

Autopilot optimal control polynomial systems identification

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References

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LQG adaptive ship autopilot

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